My only suggestions are: 1) Don't use Bullseye for this application, and 2) Be very, very careful!
The only published reference I've been able to find for heavy bullets in the .44 Special is Brian Pearce's article in Handloader #236. He tested a Dry Creek 307gr lead SWC bullet load using H110, but the load generates about 25,000 psi, so wouldn't be suitable AT ALL for your Uberti (as a reference, SAAMI maximum average pressure for the .44 Special is 15,500 psi). Pearce recommends that all Colt SAA clones (of which the Uberti is one) be limited to 15,500 psi or less, and I think that's a very wise recommendation.
I'm currently working up some 290gr LSWC .44 Special loads for my Ruger Bisley Flattop, while keeping pressures within the 15,500 psi SAAMI limits. I'm using QuickLOAD and a chronometer to try and develop these loads safely. The powders I'm working with are VihtaVuori N105, Accurate #9, Alliant 2400, and VihtaVuori N110, all of which have a slower burn rate than your Blue Dot. My initial results have been good, but I wouldn't even be attempting this without the QL/chrono combination, and the strength of the Ruger to hold it all together... Also, I'm only looking for a velocity of about 850 fps from the Ruger's 5-1/2" barrel.
Best of luck in your pursuit of a truly "heavyweight" .44 Special.